I spotted this good article on using JMS MDBs using JCA Resource Adapters.
Though a minor cricisism, if you're gonna demonstrate the nice new
features of J2EE 1.4, it'd be a good idea to use the nice & clean
polymorphic API in JMS 1.1 (Connection, Session, MessageProducer,
MessageConsumer) rather than having to use all those Queue* and Topic*
If you want to play around with an open source JMS which fully supports J2EE 1.4's Resource Adapters try out ActiveMQ. Alternatively if you want an open source J2EE container that supports J2EE 1.4's JCA for deploying RARs, give Geronimo a whirl